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4- Sheets--Sheeb 1.

(No Model.)

W. B. (BRIGHTON. STEAM 0E OTHER FLUID PRESSURE ENGINE.

Patented Ma.y 17,18918.

4 Smets-Sheet 2.

(No Model.)

W. VB.4CRICE['I'01\I. STEAM '0R OTHER FLUIDPRBSSURB ENGINE.

No. 604,109. Patented-May 17', 1898-.

n. W l www J. M

(No Model.) 4 Sheets-Sheet 3.

W. B. CRICHTON.

STEAM 0E o'EEEE ELUID EEESSUEE ENGINE. No. 604,109. 1 Patented May 17,1898.

(No Model.) 4 sheets-sheen 4.Y

W. B. CRICHTON. l v

STEAM 0R OTHER FLUID PRESSUBEBNGINE. No. 604,109. l Patented May 17,1898.

{NHE STATES ATENT Fries,

WILLIAM BA'IEMAN ORIOHTON, OF BRADFORD, ENGLAND.

SPECIFICATION formingpart of Letters Patent No. 604,109, dated `May 17, 1898. Application filed September 16, 1896. Serial. N; 605,998. (No modelli T0 all whom, zt may concern:

Be it known that I, WILLIAM BATEMAN CRICHTON, a subject of the Queen of England,

residing at Bradford, England, have invented certain new and useful Improvements in Steam or other Fluid Pressure Engines, of which the following is a specification.

This invention relates to fluid-pressure en- ;gines, and particularly to the valves and their related parts in single-acting engines.

The term single-actingengine is in this specification and its claims meant to include not only an engine with one cylinder which is single-actin g, but also a singleeacting cylinder in an en gine which may have two or more cylinders, whether the other cylinders be singleacting or not, and the term active side of the piston means that side of a single-acting piston on which the workin g fluid acts in producing the eective stroke, the other side being termed the idle side. i

One of the objects of this invention is to improve the Working of single-acting engines and render their running smoother by pro viding means whereby a suitable compression in the cylinder is obtained, another object being the provision of means to enable the amount of compression to be varied to suit the different speeds at which the engine under different conditions may run.

According to one part of this invention the compression is regulated and the running of the engine improved by a novel equilibrating and exhaust valve distinct from the admission-valve and so arranged and operated in vrelation to special ports and passages that during the first part of the period of exhaust from the active side of the piston it permits the working Iiuid to iiow from the active to the idle side thereof to put both sides of the piston in equilibrium and afterward causes the idle side of the piston to be put into communication with the atmosphere or the condenser, or otherwise effects what is ordinarily understood as the operation of exhaust. The combined equilibrating and exhaust valve is hereinafter described, by way of example, as a slide-valve, although it need not necessarily be so.

According to another part of this invention means are employed, preferably in conjunction with an equilibrating and exhaust valve of the kind above referred to, whereby some of the exhaust iiuid can be diverted out` of the engine during the equilibration of the piston, so as to lower the pressure onboth sides of the-piston for the purpose of insuring that the working iiuid shut in before the return-A ing piston shall not be at so high a pressure as to give rise to excessive compression. If the engine is intended to work under condi tions which are practically constant, the devices employed for i diverting the exhaust Iiuid, as aforesaid, can be fixed or permanent, butit is preferable that they should have an adjustable valve, hereinafter termed the pressure-red ucing or auxiliary valve, so that the amount of exhaust fluid diverted can be varied, if desired. For instance, this valve would be fitted to all engines which normally exhaust into a condenser, but which may at times be required to work non-condensing, so as to enable the engine to exhaust more freely when exhausting into the atmosphere than when exhausting into the condenser. The auxiliary valve would be of service also to regulate the amount of compression in accordance with variations in the vacuum when the engine is exhausting into the condenser.

A further part of this invention comprises an engine with two sets of cylinders, each arranged tandem fashion. The two cylinders of the lower pair have each a valve for equilibration and exhaust of the kind hereinbefore described and have a single-admission-valve chamber with a single-admission valve in it performing the functions of admission only for both the cylinders of the lower pair. One end of this valve controls the admission of the Working fluid to one of the cylinders and the opposite end of thevalve controls its admission to the other cylinder. Preferably this valve is placed between the two cylinders which it controls.

In the accompanyingdrawings, Figure lis a vertical central section through the cylinder and valve-chests of a single-cylinder singleacting engine tted with the auxiliary valve and constructed according to this invention. Fig. 2 is a sectional plan on the line 2 2 of Fig. 1, parts of the exhaust-valve chamber immediately above the plane of section being indicated in chain-lines. Fig. 3 is a vertical section on the line 3 3 of Fig. 2. i FigntV is a IOO vertical section through the four cylinders of a double tandem compound engine with op,- posite cranks and single equilibrating and exhaust valve for each of the low-pressure cylinders, a single steam-admission valve serving both those cylinders, all according to the vpresent invention; and Fig. 5 is a plan of the engine shown in Fig. 4, partly in section,on the line 5 5 of Fig. 4.

Like letters and iigures indicate like parts throughout the drawings.

With reference rst to Figs. 2 and 3, A is the cylinder. B is the piston. C is the admission-valve, and D is the valve-chest therefor. J is the piston-rod. All these parts are substantially the same as are used ordinarily in similar engines and operate for the usual purposes. There is, however, a material difference between this engine and ordinary enat its upper end-that is to say, from the active side of the piston B-into the upper end of the valve-chest L.

L2 is a port leading from the lower vend of the valve-chest L into the lower end of the cylinder E.

L3 is a port leading from the valve-chest L at a point just below the port L to the exhaust-opening L4, connected with the condenser or atmosphere or otherwise arranged to divert the exhaust-steam out of the engine.

The equilibrating or exhaust valve K in lits central position or thereabout closes both the ports` L and L3, as in Fig. l.

The ports L Lsare formed, as is customary, in a portion of the valve-chamber L in which the piston-valve K its and slides, the valve being of such axial length and so set that when the piston is at the top vof its stroke the port L is shut, and also that it shall move down to uncover the port L at the desired point in the downstroke of the piston B at` which it is desired to put the active and idle sides kof that piston into equilibrium. Such equilibration is effected by allowing the steam to iiow from the active side of that` piston through the port L and through a passage M, Figs. 2 and 3, connecting the upper and lower parts of the valve-chamber L, and by way of the port L2 into the bottom end of the low-pressure cylinder. The equilibrium and :exhaust valve K then moves upward and after having closed the port L opens the port L3, leading to the exit L4, whereupon thel steam from the lower side of the piston B exi In the operation described the pressure of the equilibratin g steam is practically constant throughout the operation of equilibration; but it is possible to lower the pressure of the equilibrating steam and thereby control the The equilibratpressure existing at the moment when the equilibrating and exhaust valve K shuts in some of the equilibrating steam above the piston for compression; and it is obvious that by controlling the pressure existing in the cylinder at the commencement of 4compression the amount of compression may be regulated as desired. To lower the pressure for this purpose, some of the exhausting iiuid can be diverted out of the engine. For this purpose it is preferable, unless the conditions under which the engine operates are constant, to employ the combination with the equilibrating and exhaust valve operating as described,v the pressure-reducing or auxiliary valve o to control the amount of the working iiuid diverted in accordance with the differing amounts of .compression which maybe desired to suit diierent speeds of the engine or differences in the working conditions.

From Figs. 2 and 3 it will be seen that the equili'brating and exhaust valve K is closed at its upper end by a diaphragm K2, so that there is no vclear passage-Way through it, the passage M in the valve chamber leading around the valve from one end to the other. Around the middle portion of the valve-chamber proper is an exhaust-jacket N, quite distinct from the passage -way M. Into this jacket the port L3 opens, and from this exhaust-jacket connection is made with the condenser or atmosphere by way of the opening L4. ln the wall N of the jacket N, between the latter and the passage M, is `an opening M under the control of the auxiliary valve O, which can be operated from outside the engine inv any manner desired-for instance, by the hand-wheel O', secured on the spindle O2, which is screw threaded and passed through a screw-threaded guide on the wall M2 of the passage M. As the steam to equilibrate the piston B passes from the port L past the upper end of the equilibrating and exhaust valve K and into the passage M to` ward the port L2 part of it can be diverted through the jacket N and passage L4 to exhaust by opening the valve O, thus varying, as may desired, the pressure available in the operation of equilibration, and consequently affecting to a proportionate extent the amount of the compression obtained when a `portion IOO IIO

of the equilibrating steamv is shut in by the return of the equilibrating and exhaust valve K upward over the port L.

If desired, the pressure-reducing valve AO may be caused to close entirely the passage M. In this case none oi the -equilibrating fluid is diverted. In some cases the valve O may be dispensed with and the passage M be made of such a size as to regulate the iiow to an extent which will give the required com,- pression. This arrangement would be adopted in the case of engines working under constant conditions of speed, load, and back pressure in the exhaust-pipe.

In the engine shown in Figs. 4 and 5, A are the high-pressure cylinders, B the highpressure pistons, E the` `low-pressure cylinders, and F the low-pressure pistons. The. crank-shaf t P is provided with two cranks P P2, set at one hundred and eighty degrees apart and each operated by one pair of the tandem pistons B F through connecting-rods Q' Q2, respectively. Eachof the cylindersE has its own equilibrating and exhaust valve K, operating substantially as and for the purpose hereinbefore described. The low-pressure steam-valve G and its valve-chest H are situated between the two cylinders. The'upper edge G of the valve G operates to control the steam-admission port E2, leading from the valve-chest into one of the cylinders E, and the lower edge G2 operates to control the port E3, leading into the othercylinderE. By reason ofthe cranks P P2 being set at one hundred and eighty degrees apart the operations of steam distribution in one cylinder E are alternate with the like operations in the other cylinder E, so that the port E2 is closed when the port E2 is open, and vice versa, and as these ports E2 E3 are respectively disposed near opposite ends of the valve G it follows that if that valve be, for instance, moving up, its upper edge G will close the vport E2 while its lower edge G2 opens the port E3, the converse operation taking place when the valve descends. If a single steam-valve be employed in this manner for both the cylinders E,A it is placed between the two cylinders in the manner indicated in Figs.' 4 and 5 and operated by an eccentric or other valve-operating device suitably set upon or controlled from the crank-shaft P and enables a very simple and compact engine to be produced.

It is to be clearly understood that the valve G is used only for admitting steam to both cylinders E and that it does not effect any of the other operations of distribution of the working fluid.

Although no valve O is shown in connection with the passage M, Fig. 5, it is obvious that one might be fitted therein in the manner previously described with reference to Fig. 2.

Conveniently the valve spindle G3 of the valve G can be extended upward, as shown, to operate an ordinary steam and exhaust piston-valve C, controlling both the highpressure cylinders A.

The piston-valves hereinbefore referred to maybe solid` or recessed cylindrical bodies provided with piston-rings, grooves, or otherwise made steam-tight, or llat valves or rotary valvesmay be employed.

No special mention has hereinbefore been made of the remaining details of the engines illustrated, for they may be suchas are customarily employed in similar cases. i

Live steam from the boiler enters by the pipe l (seen dotted in end elevation in Fig. 4) an annular chamber 2, cored out in the casting of the high-pressure cylinders. From this casting it passes through a ring of ports 3 (always open) in a liner 4, placed in the valvechest D, which is common to both the highpressure-cylinders A. There are other rings of ports 5 and 6 in the liner 4, which'are re-` spectively above and below the ports 3. The ports 5 are opposite the passage-way 7 only,

vwhich is formed so as to extend from the top end of the left-hand cylinder right around the liner. The ports 6 are opposite a similar passage 8, by which they can be put into communication with the top end of, say, the righthand high-pressure cylinder A.

\ 9 is a tubular piston-valve with an annular cavity l0, form ed around its exterior between its ends. In the reciprocation of the valve this cavity 10,which is always in communica# tion with the steam-space 2, puts that steamspace into communication alternately with one or other of the sets of ports 5 or 6 and so supplies alternately the cylinders A with steam. ward, it puts the steam-supply space 2 in communication with the top of the left-hand high-pressure cylinder by way of the ports and the passage 7. When it moves downward, it shuts oft communication between the steam-space 2 and the left-hand cylinder and opens communication between that space and the right-hand high-pressure cylinder by way of the ports 6 and passage 8. When the valve is thus giving steam to the top end of one c'yl'- inder, the top end of the companion cylinder is exhausting, the exhaust-steam returning by the passages 7 or 8, as the case may be, through the liner and past the upper or lower IOO When the piston-valve 9 moves upend of the piston-valve, llling the tubularvv interior of the valve and the valve-chest D and also the lower ends of thehigh-pressure cylinders by way of the passage lland iilling also the low-pressure valve-chest H, which is always in communication with the chamber D.

The volume of the space into which the highpressure steam is exhausted remains practically constant, because of the alternate action of the high-pressure pistons, and at the saine time drag upon such pistons, by reason of the tendency to 'create a vacuum beneath them, is entirely avoided. From the valve-chest H the valve G admits the high-pressure exhauststeam alternately to the cylinders E above the low-pressure pistons F, and from thence the steam is exhausted by means of the equilibrating-valves K in the manner hereinbefore described-that is to say, when either of said pistons F commences its upstroke the steam passes from above it through the port L and passage M to the lower side of the piston F, the port L is closed just before the piston F reaches the upward limit of its movement, and the exhaust-port L3 is opened, throwing the lower side of the piston F into communication with lthe exhaust or condenser, and, if desired, the pressure of the steam so confined above the low-pressure piston F is regulated by means of the reducing-valve O, which controls the quantity of steam escaping directly to exhaust from the upper side of the piston F.

I claiml. 'In a steam-engine, the combination with the cylinder and independent valve-chests, with ports opening communication with one of said valve-chests and the upper end of the cylinder, ports communicating between the other of said valve-chests and both ends of the cylinder, with an independent passagev connecting the last-mentioned ports with each other and an exhaust-port, of a piston workin g in said cylinder, independent valves located in said valve-chests and controlling said port-s, one to admit pressure to the upper end of the cylinder and the other to control the exhaust therefrom, and to control the by-pass from the upper to the lower end of the cylinder; substantially as described.

2. In a steam-engine the combination with the cylinder, and independent Valve-chests, with ports opening communication with one of said valve-chests and the upper end of the cylinder, ports communicating between the other of said valve-chests and both ends of the cylinder, with an independent passage connecting the last-mentioned ports and an exhaust-port, of a piston working in said cylinder, valves controlling said ports and the pressure-reducer located in the passage bex tween the upper and lower ends of the cylin der; substantially as described.

3. In a steam-engine, the combination with the cylinder, independent Valve chambers with ports communicating with one of said valve-chambers and the upper end of the cylinder and between the other of said valvechambers and both ends of the cylinder with an independent passage connecting the lastinentioned ports and an exhaust-port, a piston working in said cylinder and valves controlling the said ports, of a pressure-reducin g valve interposed between the ports communicating with both ends of the cylinder, with means for manually controlling the said pressure-reducing Valve; substantially as described.

4. In a steam-e'ngne-the combination with the two cylinders arranged side by side, an intermediate Valve-chest with ports opening communication between said valve-chest and the upper ends of both said cylinders, and independent valve-chests with ports opening communication between both ends of said cylinders and said independent valve-chests, and pistons Working in said cylinders, of a valve working in said intermediate Valvechest and controlling the admission of pressure to the upper ends of the cylinders alternately, and independent valves located in said independent valve-chests and controlling the ports leading from opposite ends of the cylinders to exhaust; substantially as described.

5. In a steam-engine the combination With the cylinders arranged side by side, the intermediate and independent Valve-chest with ports leading from the intermediate valvechest to the upper ends of both the cylinders and from the independent valve-chest to both ends of the cylinders and to exhaust, and a passage M in each of said independent valvechests, of pistons working in said cylinders and Valves working in said Valve-chests, and controlling, respectively, the alternate admission of pressure to the upper ends of the cylinders and the alternate admission of pressure from the upper ends of said cylinders through the passages M, to the lower ends of said cylinders, and from the lower ends of said cylinders to exhaust; substantially as described.

In testimony whereof I have hereto set my hand in the the presence of two subscribing witnesses.

WILLIAM BAIEMAN CRICHTON.

Witnesses: y

A. W. PosTLETHWAITE, E. HUBBARD. 

